Industrial vending machines are known. There are a number of different designs. The majority generally utilise a variety of converted drinks and confectionary machines. Such machines have a number of limitations; most notably that stored items usually require repackaging and/or are dropped from a height into a receiving tray, which is inappropriate for high value precision goods or delicate items.
There exists a small number of application-specific machines that have been designed to directly address the needs associated with the controlled dispensing of high value goods. Such machines generally comprise a plurality of drawers, each containing a plurality of compartments, each compartment containing a stored item. In one such known machine, each individual compartment can be opened by the release of a lid on that compartment. The release is effected by means of a solenoid-operated latch. In an alternative design, a drawer is allowed to be pulled out to a prescribed distance from the body of its cabinet such that a specific compartment in the drawer may be accessed, the withdrawal distance being defined by a computer, at which point it is locked such that further withdrawal is prevented, thereby allowing access to a specified compartment within the drawer. Again, the locking and release of the drawer is controlled by means of a solenoid-operated latching mechanism.
These designs all have a common feature in that each drawer or compartment requires a release/locking mechanism, comprising a solenoid and sensor system for open/close sensing and distance measurement. A significant number of these mechanisms is required in each machine; almost a 1:1 ratio of compartments and mechanisms is required. In order to provide a machine with adequate capacity for secure storage of individual items for it to be useful, such machines typically comprise in the region of eighty solenoid mechanisms.
Furthermore, such solenoid sensor mechanisms require the solenoid locking mechanism only to be actuated once the sensor means indicates to the control system that the drawer has been withdrawn from the cabinet to the required distance. Disadvantageously, such systems can fail because it can be possible to pull a drawer out more quickly than the latching mechanism can lock it, due to the inherent inertia in the solenoid mechanism and electrical delays. It is therefore possible to defeat the locking mechanism, leading to unauthorised access to restricted compartments.
Such systems thus require many components, which are expensive and bulky and such systems are not always secure.
It is desirable to provide a secure dispensing system in which the number and complexity of the locking parts is reduced. It is desirable to overcome problems associated with being able to defeat the locking mechanisms of the prior art by rapid withdrawal of the drawer.
The present invention seeks to provide an improvement in the field of dispensing systems for storage and controlled access of articles that has particular application for high value articles such as tools, computer and electrical components, parts in automotive manufacture and the like. The present invention provides a mechanical arrangement for locking and releasing drawers and controlling access to individual drawer compartments, and provides a mechanism for pre-selecting the withdrawal distance prior to releasing the selected drawer.
The invention may be utilised in applications other than for high value articles. For example, it is foreseen that the invention may have application in warehouses, offices, shopping malls and on construction sites and the like, where there is a benefit to providing on-location secure storage and controlled access of articles.